Bonding to dentin as a function of air-stream temperatures for solvent evaporation

Abstract

This study evaluated the influence of solvent evaporation conditions of acid-etching adhesives. The medium dentin of thirty extracted human third molars was exposed and bonded to different types of etch-and-rinse adhesives: 1) Scotchbond Multi-Purpose (SBMP) ; water-based; 2) Adper Single Bond 2 (SB) ; ethanol/water-based, and 3) Prime & Bond 2.1 (PB) ; acetone-based. Solvents were evaporated at air-drying temperatures of 21ºC or 38ºC. Composite buildups were incrementally constructed. After storage in water for 24 h at 37ºC, the specimens were prepared for bond strength testing. Data were analyzed by two-way ANOVA and Tukey's test (5%). SBMP performed better when the solvents were evaporated at a higher temperature (p < 0.05). Higher temperatures did not affect the performance of SB or PB. Bond strength at room temperature was material-dependent, and air-drying temperatures affected bonding of the water-based, acid-etching adhesive.

Dentin pretreatment and adhesive temperature as affecting factors on bond strength of a universal adhesive system

“…In this study, however, pre-heating of the adhesive did not significantly alter the bond strength, except when associated with aluminum oxide groups; thus, the second hypothesis tested was partially accepted. This finding corroborates some studies, which concluded that increase in temperature had no significant effect on an adhesive based on ethanol/water, similar to the SbU tested in this study 11 , 13 . Other studies showed that higher immediate bond strength was associated with the highest temperatures for enamel (40°C) 1 and dentin (50°C) 18 ; however, the adhesive systems that presented these results are classified as etch-and-rinse adhesives, thus being different from the SbU.…”

“…Thus, the solvents and the water present in the adhesive should ideally be removed to a sufficient degree because residual solvents can inhibit the polymerization and negatively affect the mechanical properties of the adhesive 16 , 26 . Hence, a clinical approach to improve the adhesive properties indicates the use of warm air 9 , 13 , 16 , 19 , 20 , 26 to facilitate the evaporation of the solvent as well as the use of preheated adhesive systems 11 , 18 , 25 , 28 in order to increase the speed of permeation of the monomers and the evaporation of the residual monomeric content. The quality and the stability of the hybrid layer can be influenced by the heating of adhesive through the stimulation of their chemical reactions and, thus, some properties of the monomeric solutions, such as degree of monomer conversion and viscosity, can be changed by temperature 1 , 11 , 18 , 23 , 28 .…”

Effect of different air-drying time on the microleakage of single-step self-etch adhesives

“…Acetone has higher vapor pressure and lower boiling temperature when compared to alcohol, which translates into faster evaporation of it 9. However, it was reported that even for an acetone-based adhesive, spontaneous evaporation exhibits only after 5 minutes of its application, which is clinically unacceptable 19. Furthermore, the adhesives used in the present study contain HEMA, which is a co-monomer that acts as a wetting agent and diffusion promoter for resin 21.…”

“…The tested adhesives contain different types of solvents, OBAO, acetone and ethanol; BF, isopropyl alcohol; CSB, ethanol. Water is a poor solvent for hydrophobic monomers, so alcohol or acetone is added to the solution 19. Alcohol has higher vapor pressure compared to water and provides better evaporation by air-drying 14.…”

Clinical observation of the tooth surface during air-drying of self-etching primer under 3D video microscope

“…Therefore, all cases were performed by the same operator. In addition, since the temperature of the blown air affects the bond strength of self-etching primer [15,18,19], all cases were performed in the same unit (Silona M1-F).…”